Plunger pump



Patented June 19, 1934 PATENT Aori-"regral' PLUNGER PUMP Ernst Schaeren,

to Scintilla Switzerland Solothurn, Switzerland, assignor Aktiengesellschaft,v Solothurn,

Application September 3, 1932, Serial No..631,700 In Germany September 18, 1931 4 Claims.

-The invention relates to plunger pumps the suction and pressure channels of which are controlled by slide valve gears, andthe Working plunger and theslide valve of the same being ar- 'd ranged in parallel to each other, but set apart the latter type of pumps,

l pump cylinder are from one another at an angle of 90 in the cycle of operation.

In plunger pumps of this kind as hitherto known the working plungers and the slide valves are operated by means of two driving discs obliquely disposed with respect to the axis of rotation or by means of a separate eccentric for eachV member. In the case of the former type of pumps a high relative speed of the driving disc to the adjustable member of the plunger takes place,

l operation of the plunger vtouch each other, but

in a line, high specific pressures are set up resulting ina rapidwear of these members.

According to the present invention the working plungers and the slide valve provided per driven off a common closed eccentric. n

In the drawing a constructional example of the subject of the -invention is illustrated. y

Fig. 1 is a section yof the pump on the line M-N if of Fig. 2.

l the pressure channel.

Fig. 2 is alongitudinal section of the pump on the line A--Bl-C--D and on the line E-F of Fig. 1. f f

Fig. 3 is a the pump. w l

-In the iigures a,l is thepump body, which 1s screwed on to the side wall-,of the pump house ing zr. b is the working plunger and c the slide valve. d represents the suction channel and e f is a lever pivotally mounted on the xedpin 7c impartingv an axial movement to the working plunger b. By means of the screw q which is locked by the screw r in the lever f, the axial play between the working plunger b and the lever'f is adjusted. The lever f is turned by the double armed reccentric lever g connected to the former by means of the pinl. The double armed leverV g forms a closed ring around the eccentric h'which is keyed to the shaft further constructional example of 'nl i. The vdouble armed lever r/.has a pin m on the (Cl. S-e227) opposite side l01E the lever f, engaging a slot of a cranky lever n.- The crank lever n is pivotally. mounted on the nxedpinp imparting the necessary axial movementto the slide valve c.. The shaft i is driven off the shaft u b y means of the gears s-t and said shaft uin its turnis rotated by the lever v which is coupled to the ,shaft u in a known manner, by way of example, using a ratchet wheel. 1

VThe drive of the working plunger and the slideY valve is made, as known,` in; such a way that inthel change cf stroke of the working plunger when the speed is reduced to nought, the sleeve valve lis approximatelyin the middle `of its stroke having the maximum` speed, i.,e.` the periodical movef 70 ments` off the kworking plunger and the sleeve valve are set apart from one another at angangle of 90 Vin the cycle of operation. lThis is necessary in order that the moment the suction channel is closed,'the pressure channel is quickly uncovered, thus preventing an inadmissibly .high increase of pressure in the pump vchamber o during the rst part of the pressure stroke. According to the invention both pistons are set apart in the cycle of operation by means of a single eccentric in connection'with a crank lever vand in order to obtain a displacement of the condition must .be fullled in the dead centre of the working piston, that the points G-I-I-f-I-K and L are lying in one straight line, G being the centre of the' pin l, H the one Yof the eccentric h, I the centre of the shaft 1'., K the one of the pin m and L the one of the pin p.

If the fulcrum L of the crank lever n is not lying on this line', the maximum speed. of the 90 sleeve valve 'would not coincide with vthe position of the working plunger in the dead centre; in this case the speed imparted by the eccentric lever g to the crank lever 11di'rected in 'the dead centre of the working plunger rectangularly to said straight line Yand having a maximum value, would not be fully imparted to the crank lever, but with a smaller component only; Y

'In the position shown in Fig. 1 the working plunger starts itsdownward stroke whilstthe 100 sleevefvalve is moving upwards with maximum speed uncovering the channed e. The liquid enclosed in the pump chambero is then delivered throughthe channel e and via the recess w of the sleeve valve to the pressure channel e. When the rworkingy plunger has reached its lowest/position and delivered allthe liquid out of the chamber o, Vthe sleeve valve has returned again `to the position killustrated inA Fig. 1, Yi.,e. closes. again; the Channel @and Connetheucl otally fixed to said pump casing,

tion channel d with the pump chamber o. The working plunger moves upwards and the pump chamber o is filled up with liquid until the plunger has reached again the position of Fig. 1. The suction channel is again shut off and the cycle of operation is repeated as described above.

The sleeve valve c by having a recess w works as a balanced piston, thereby reducing the pressure on the crank lever n practically to nought; the result thereof is that the wear on the sliding parts of the piston and the lever and the pin m is diminished. On the other hand the movement of the screw q relative to the piston b is small; and further the pin Z and the eccentric h are enclosed all around by the eccentric lever g with the result that the specific pressure between these parts engaging one another and consequently the wear too is very small. Because of the crank lever n a second eccentric is not necessary beside that for the working plunger as used in well known arrangements and therefore the overall length of the pump is reduced by half the amount.

Another constructional example according to the invention is given by an arrangement in which on the right and left hand side of the eccentric lever g, a pump body a comprising a working plunger and a sleeve valve is provided. This example is shown in Fig. 3. rangement the levers f and 1L are disposed symmetrically with respect to the line lc-p and likewise the pump bodies a with respect to the same line.

A further advantage of the application comv pared with known arrangements is the ease with which the pump housing and drive mechanism can be dismounted. As the pump bodies a are screwed to the side wall of the pump housing, the pump bodies together with the pistons and its drive members can easily be taken out after having unscrewed the screws without loosening the connections of the pressure pipes.

What I claim is:

1.,In a plunger pump in combination a pump casing, pump cylinders, working plungers and sleeve valves, the latter being set apart from one another with respect to their periodical movements at an angle of 90 in the cycle of operation, one working plunger and one sleeve valve at least being arranged per pump cylinder, a common eccentric per pump cylinder, a two armed eccentric lever, a one armed lever, a crank lever, these two latter levers pivotally Xed to the pump casing, a pin Iixed to one arm of said eccentric lever for the drive of said working plunger, a pin fixed to the second arm of said eccentric lever for the drive of said sleeve valve, these two pins being arranged diametrically opposite one another with respect to the centre of the bore of said eccentric lever, one of said pins adapted to drive the working plunger being guided in a circle, the other pin engaging said crank lever for the drive of said sleeve valve.

2. In a plunger pump in combination a pump casing, pump cylinders, the latter being screwed to the inside wall of said pump casing, pressure pipe connections disposed in the pump casing proper, working plungers and sleeve valves, being set apart from one another with respect to their periodical movement at an angle of 90 in the cycle of operation, one working plunger and one sleeve valve at least being arranged per pump cylinder, a common eccentric per pump cylinder, a two armed eccentric lever, a one armed lever, a Acrank lever, these two latter levers piva pin iixed to In this arone arm of said eccentric lever for the drive of said working plunger, a pin fixed to the second arm of said eccentric lever for the drive or" said sleeve valve, these two pins being arranged diametrically opposite one another with respect to the centre of the bore of said eccentric lever, one of said pins adapted to drive the working plunger being guided in a circle, the other pin engaging said crank lever for the drive of said sleeve valve.

3. In a plunger pump in combination a pump casing, pump cylinders, the latter being screwed on to the inside wall of said pump casing, pressure pipe connections disposed in the pump casing proper, working plungers and sleeve valves being arranged parallel to each other and set apart from one another with respect to their periodical movement at an angle of 90 in the cycle of operation, one working plunger and one sleeve valve at least being arranged per pump cylinder, a common eccentric per pump cylinder, a two armed closed eccentric lever, a one armed lever, a crank lever, these two latter levers pivotally fixed to said pump casing, said common eccentric being disposed between said one armed lever and said crank lever, said working plunger which is slidably connected to said one armed lever and said sleeve valve which is slidably connected with said crank lever, being arranged nearly above one another, a pin Xed to one arm of said eccentric lever for the drive of said working plunger, a pin fixed to the second arm of said eccentric lever for the drive of said sleeve valve, these two pins being arranged diametrically opposite one another with respect to the centre of the bore of said eccentric lever, one of said pins adapted to drive the working plunger being pivotally connected to said one armed lever, the other pin engaging a slot in one arm of said crank lever for the drive of said sleeve valve.

4. In a plunger pump in combination a pump casing, pump cylinders, the latter being screwed on to the inside wall of said pump casing, pressure pipe connections disposed in the pump casing proper, working plungers and sleeve valves being arranged parallel to each other and set apart from one another with respect to their periodical movement at an angle of 90 in the cycle of operation, one working plunger and one sleeve valve at least being arranged per pump cylinder, a common eccentric per pump cylinder, a two armed closed eccentric lever, a one armed lever, a crank lever, these two latter levers pivotally Xed to said pump casing, said common eccentric being disposed between said one armed lever and said crank-lever, said working plunger which is slidably connected to said one armed lever and said sleeve valve which is slidably connected with said crank lever, being Varranged nearly above one another, a pin xed to one arm of said eccentric lever for the drive of said working plunger, a pin xed to the second arm of said eccentric lever for the drive of said sleeve valve, these two pins being arranged diametrical- 1y opposite one another with respect to the centre of the bore of said eccentric lever, one of said pins adapted to drive the working plunger being pivotally connected to said one armed lever, the other pin engaging a slot in one arm of said crank lever for the drive of said sleeve valve, said pump bodies being symmetrically arranged on each side of the connecting line of the fulcrum of the drive lever of the working plunger and of the fulcrum of the crank lever for the sleeve valve. ERNSTY SCHAEREN. 

